Author: Graham Brennan, transport and ocean R&D programme manager, Sustainable Energy Authority of Ireland
In part one of this two-part article, we examined the engineering effort required to develop a successful wave energy converter (WEC) device. Now we will consider, from the perspective of a developer or investor, the type of commercial environment needed in order for a wave-energy industry to flourish here in Ireland.
An energy utility company is in the business of making profit from electricity sales and will choose the most cost-effective technologies to invest in. Following a long period of development and a gradually increasing price of oil, wind power finally made a commercial breakthrough in the 1990s.
The cost of electricity delivered from a combined cycle, gas-turbine power station based on current gas prices is about 6 cent per unit (i.e. kWh) of electricity produced. Similarly, the cost of electricity from a wind farm in Ireland today is expected to be 7 cent/kWh. Any differences in price are subsidised via a feed-in tariff which is paid for by all electricity consumers.
A WEC manufacturer wishing to succeed today, without major subsidies in place, would need to sell devices capable of producing electricity within this price range. The goal of the designer is therefore to minimise the capital costs and maintenance costs, while maximising the energy efficiency and reliability of any potential device.
The obvious reaction may be to aim to develop the offshore sites with the highest wave energy levels and therefore maximise electrical output. However, for the first sites to be of commercial significance, a couple of important factors should also be considered.